JPH11103335A - Cordless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate noises and uncomfortable feelings by performing control so as to prevent a ring back tone from being sounded when a radio wave transmitted from a base unit is stronger than prescribed strength at the reception position of a hand set. SOLUTION: On the side of a hand set 7, a signal f1 of a control channel and a calling signal f2 are selected by a 1st band filter 8, amplified by a high frequency amplifier circuit 9 and supplied to a mixer circuit 10. A local oscillation signal is supplied from a local oscillation circuit 11 to the mixer circuit 10, a signal converted into an intermediate frequency appears, a signal corresponding to the signal f1 is extracted from a 2nd band filter 12, and this signal is detected by a detection circuit 14 and compared by a comparator circuit 15 so as to discriminate whether it is higher than a prescribed value or not. A ring back tone signal corresponding to the frequency modulated calling signal f2 appears at a 3rd band filter 13 but a switching circuit 16 is serially connected to a transmission line for that signal and when a control. signal to appear at the comparator circuit 15 is higher than the prescribed value, the switching circuit 16 is disconnected so that the ring back tone is not supplied to an amplifier circuit 17 for the ring back tone signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless communication system such as a cordless telephone, a portable radio telephone, and a pager having a master unit connected to a communication line and a slave unit wirelessly connected to the master unit. More specifically, it suppresses the battery consumption of the slave unit of such a cordless communication system and also suppresses the ringing sound of the communication system from both the master unit and the slave unit and giving discomfort as noise. The present invention relates to a cordless communication system.

[0002]

2. Description of the Related Art Conventionally, when a call is received from the outside in a base unit or a handset of a cordless telephone device having a handset, a ringing tone or a call display is displayed at a certain time or a specific place as required. For example, Japanese Patent Laid-Open No. 5-3
No. 509. In addition, power is supplied to the master unit from a commercial AC power supply or a repeater unit, but the slave unit is driven by a battery or charging station built in the slave unit, so it is necessary to minimize the consumption of the battery. There is a problem that it does not.

[0003]

SUMMARY OF THE INVENTION According to the present invention, in a cordless communication system having a handset, the battery consumption of the handset of the same communication system is suppressed, and when an incoming call is received from outside, the ringing tone of the communication is reduced. To prevent discomfort as noise coming out of both the handset and the handset, a specific system that prevents the handset from ringing when the base unit and the handset are close to each other To provide.

[0004]

According to a first aspect of the present invention, there is provided a cordless communication system, comprising: a base unit connected to a communication line; a base unit wirelessly connected to the base unit; And a ringing circuit for receiving a ringing tone signal and generating a ringing tone, wherein the radio wave transmitted from the master unit is stronger than a predetermined strength at the receiving position of the slave unit. A comparison circuit for comparing whether or not the ringing tone signal is output from the parent device when the output of the comparison circuit is greater than a predetermined value, and the ringing circuit is controlled not to sound a ringing tone even if a ringing tone signal is received from the master unit. Means are provided in the slave unit.

In the cordless communication system according to the present invention, a signal of a control channel is used as a radio wave transmitted from the master unit. Further, in the cordless communication system according to the third aspect, the radio wave transmitted from the master unit uses a signal of a communication channel. A cordless communication system according to a fourth aspect of the present invention includes a delay circuit before the ringing circuit of the slave unit, and transmits a radio wave transmitted from the master unit as needed. Furthermore, claim 5
In the cordless communication system described in (1), a means for controlling so as not to sound the ringing tone is a switching circuit controlled by an output of the comparison circuit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block circuit diagram showing one embodiment of the cordless communication system of the present invention. In FIG. 1, transmission / reception signals are transmitted from a general subscriber telephone network 1 to a base unit 2 of a cordless telephone device via a wired line. Then, the transmitter 4a and the receiver 4b are transmitted via the internal control device 3.
Transceiver 4 comprising a handset, handset 5 comprising a handset
The signal is transmitted to the transmitting / receiving antenna 6. In addition, the handset 7 of the cordless telephone device transmits a signal to the transceiver 4 'including the transmitter 4a' and the receiver 4b ', the handset 5', and the transmission / reception antenna 6 'via the control device 3'.

FIG. 2 is a block circuit diagram of a main part showing an electrical configuration of one embodiment of the cordless handset 7 of the cordless telephone apparatus according to the present invention. In the present invention, a control channel signal (f1) used between the master unit 2 and the slave unit 7
For example, a weak signal of a low level in the 380 MHZ band is always output from the master unit. Further, when there is an incoming call to the base unit 2 from outside, a ringing tone signal from outside is also transmitted from the base unit 2 to the slave unit 2 as a calling signal (f2). On the slave unit 7 side, the transmitting / receiving antenna 6 ′ is connected to a first bandpass filter 8, and the filter 8 controls the signal of the control channel.
(f1) and the calling signal (f2) are selected. These signals f
1 and f2 are amplified by the high frequency amplifier circuit 9 and
Supplied to A local oscillation signal is supplied from the local oscillation circuit 11 to the mixing circuit 10, a signal whose frequency has been converted to an intermediate frequency from the mixing circuit 10 appears, and the second bandpass filter 12
And the third bandpass filter 13. A signal corresponding to the signal (f1) is extracted from the second bandpass filter 12. This signal is detected by a detection circuit 14 comprising an envelope detector and supplied to a comparison circuit 15, where it is compared whether it is greater than a predetermined value. The predetermined value is determined as follows. That is, for example, based on the value of the detection output appearing in the detection circuit 14 at a position where the master unit 2 and the slave unit 7 are separated by 2 m, when the detection output is larger than this reference value, a control signal is output from the comparison circuit 15. Set to.

On the other hand, a ringing tone signal corresponding to the FM-modulated ringing signal (f2) appears in the third bandpass filter 13, and a switching circuit 16 is connected in series with the signal transmission line.
Is connected, and when the control signal appearing in the comparison circuit 15 is larger than a predetermined value, the switching circuit 16 is cut off, and the ringing tone is not supplied to the subsequent ringing tone amplifier 17 so that the ringing from the speaker 18 is performed. No sound comes out.
Accordingly, power consumption of a battery or a rechargeable battery built in the slave unit 7 is suppressed. Further, the master unit 2 and the slave unit 7 are, for example, 4 m
When it is placed away from the remote unit, the switching circuit 16 is turned on by the control signal from the comparison circuit 15, and a ringing tone sounds from the slave unit 7.

In the above description, an example has been described in which the weak signal of the control channel signal (f1) is always output from the base unit 2. However, the base unit 2 always needs to continuously transmit a weak radio wave. For example, when there is an incoming call to the base unit 2 from outside, the base unit 2 may transmit the incoming call simultaneously with the incoming call and only for a period until the calling signal (f2) from the base unit 2 disappears. Good. that time,
A delay circuit 19 is connected to the preceding stage of the switching circuit 16, and the delay time is determined before the ringing signal corresponding to the ringing signal (f2) arrives at the switching circuit 16.
The signal corresponding to (f1) is the detection circuit 14 and the comparison circuit 15
The switching circuit 16 is set so as to be controlled to be in the cut-off state by arriving at the switching circuit 16 via. At this time, the switching circuit 16 is set so as to continue the cut-off state slightly longer than the delay time even if the control signal from the comparison circuit 15 is lost.

[0010] In this manner, even if the special control channel signal (f1) is not used from the master unit 2, the normal communication channel of the communication channel transmitted to the slave unit 7 instead of the signal (f1) is used. By detecting the carrier wave of the call radio wave by the detection circuit 14, the ringing tone of the slave unit 7 can be controlled.

FIG. 3 shows a circuit of another embodiment of the present invention using a wide band amplifier circuit. That is, a broadband filter 20 is connected to the antenna 6 ', and a broadband amplifier circuit 21, a detection circuit 14, and a comparison circuit 15 composed of an operational amplifier are connected. In this case, if the white noise falls below a certain level in accordance with the magnitude of the control channel signal (f1), the ringing tone does not sound. In the above description, the embodiment of the cordless telephone having the slave unit has been described, but it goes without saying that the present invention can be similarly applied to a portable radio telephone or the like.

[0012]

As described above, the cordless communication system of the present invention does not need to ring the handset when the position of the base unit and the handset is very close to each other. Therefore, both the parent device and the child device do not ring and give noise and discomfort, and furthermore, the energy for ringing is eliminated, and the battery and the rechargeable battery built into the child device are eliminated. The advantage is obtained that wasteful consumption can be suppressed and the battery of the slave unit can be held for a long time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a cordless communication system according to the present invention.

FIG. 2 is a block circuit diagram of a main part showing an electric configuration of an embodiment of a cordless handset of the cordless communication system according to the present invention.

FIG. 3 is a block circuit diagram showing an electric circuit configuration of another embodiment of the cordless communication system slave unit according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 General subscriber telephone network 2 Cordless telephone device base unit 3 Control device 4 Transceiver 5 Handset 6 Transmitter / receiver antenna 7 Cordless telephone device handset 8 First bandpass filter 9 High frequency amplifier circuit 10 Mixing circuit 11 Local oscillator circuit 12 Second Bandpass filter 13 Third bandpass filter 14 Detection circuit 15 Comparison circuit 16 Switching circuit 17 Amplification circuit 18 Speaker 19 Delay circuit 20 Broadband filter 21 Broadband amplification circuit

Claims (5)

[Claims] At least one base unit connected to a communication line and at least one ringing circuit connected to the base unit wirelessly and receiving a ringing signal transmitted from the base unit and sounding a ringing tone is mounted. In a cordless system including two slave units, a comparison circuit for comparing whether a radio wave transmitted from the master unit is stronger than a predetermined strength at a reception position of the slave unit, and an output of the comparison circuit being a predetermined value. A cordless telephone device comprising: a slave unit that controls the ringing circuit so as not to generate a ringing tone even when a ringing tone signal transmitted from the base unit is received when it is larger. 2. The cordless communication system according to claim 1, wherein the radio wave transmitted from the master unit is a signal of a control channel. 3. The cordless communication system according to claim 1, wherein the radio wave transmitted from the master unit is a signal of a communication channel. 4. The cordless telephone according to claim 1, wherein a delay circuit is provided in a stage preceding the ringing circuit of the slave unit, and radio waves transmitted from the master unit are transmitted as needed. Communications system. 5. The cordless communication system according to claim 1, wherein the means for controlling the ringing tone so as not to sound is a switching circuit controlled by an output of the comparison circuit.